1. Field of the Invention
The present invention relates to a honeycomb structured body, a method for manufacturing a honeycomb structured body, and an exhaust gas purifying device.
2. Discussion of the Background
Recently, particulate matters (fine particles, hereinafter referred to as PM) such as soot, contained in exhaust gases that are discharged from internal combustion engines for vehicles such as a bus, a truck, construction equipment and the like, have raised problems as contaminants harmful to the environment and the human body.
In order to solve those problems, there have been proposed various applications in which a honeycomb structured body, which comprises a honeycomb unit comprising a plurality of cells longitudinally placed in parallel with one other with a cell wall therebetween, is used as filters for capturing PM in exhaust gases to purify the exhaust gases.
As materials for a conventional honeycomb unit, porous silicon carbide, cordierite or the like is known.
As for examples of the conventionally known honeycomb structured body of this kind, a honeycomb structured body in which each corner portion of all cells are provided with a reinforcing member in order to secure strength against thermal stress (for example, see JP-A 9-299731 and JP-A 49-113789), and a honeycomb structured body in which the thickness of cell walls and the size of each cell are enlarged to secure strength for a backwashing process and also to avoid bridging of PM during the backwashing (for example, see JP-A 2-146212) has been disclosed.
Moreover, a honeycomb structured body in which each corner portion of only the cells located at the outer area are provided with a reinforcing member (for example, see JP-A 10-264125) has been disclosed.
The contents of JP-A 9-299731, JP-A 49-113789, JP-A 2-146212, and JP-A10-264125 are incorporated herein by reference in their entirety.